Field of the Invention
The present invention relates to a boosting system, a diagnosing method, and a computer readable medium storing a diagnosing program. In particular, the present invention relates to a boosting system, a diagnosing method, and a computer readable medium storing a diagnosing program, that carry out self-diagnosis of a boosting section.
Description of the Related Art
Boosting circuits, that generate boosted voltage obtained by boosting the power supply voltage of a power supply such as a battery cell or the like, are generally known. There are devices and methods for diagnosis of the boosting circuits.
For example, Japanese Patent Application Laid-Open (JP-A) No. 2000-125586 discloses a diagnosis method and device that are applied to a boosting circuit that generates the driving power supply of high-side switching elements of a reversible motor drive circuit. In JP-A No. 2000-125586, diagnosing of defect of the boosting circuit is carried out by a CPU comparing a boosted voltage VS and a voltage that is twice a power supply potential VVB.
On the other hand, a chopper-type comparator, that is disclosed in JP-A No. 2010-97549 and that connects capacitors in parallel, is known as a comparison circuit (comparator)
However, in the technique disclosed in JP-A No. 2000-125586, in order to compare the boosted voltage VS and the voltage that is twice the power supply potential VvB at the CPU, the CPU may be occupied by diagnosis, and may cause delays in other process.
Further, when the boosted voltage VS is AD-converted and inputted to the CPU, it is connected to GND at a constant voltage value, and voltage division must be carried out by using a dividing resistor. Therefore, at the time of the voltage division, electric power from the power supply line that is connected to GND is consumed. Further, detection current must be made to flow to the resistance element of the dividing resistor. However, in order to suppress consumption of the boosted output current, that is outputted from the boosting circuit, in the diagnosing of defect, the resistance value of the resistance element must be made to be as large as possible. However, there are limits to the resistance value that can be obtained, and the boosted output current that is consumed in order to diagnose defect cannot be made to be less than or equal to the current that is limited by the resistance value.